In O'Reilly v. Morse (1853), 56 U.S. 62, involved the validity of the patent to Morse for an electric telegraph. This patent contained eight claims, all of which, except the last, were for the machinery by which the electricity was transmitted and the message recorded. The eighth claim was for the use of the electric current as a motive power, however developed, for marking or printing intelligible characters at any distance. This claim was held to be too broad and not warranted by law, the court being of opinion that the allowance of such a claim would shut the door against the inventions of other persons, and enable the patentee to avail himself of any new discoveries in the properties and powers of electricity which scientific men might bring to light. The Supreme Court decided that a functional claim may be disclaimed under the disclaimer statute, 35 U.S.C.A. 65 1952 Revision, 35 U.S.C.A. 253, after a court has found it to be invalid as functional. Under the statute a disclaimer must be based on error due to inadvertence, accident, or mistake without fraudulent or deceptive intent. While the disclaimer and reissue statutes serve different purposes and were enacted to meet different problems, the Court clearly recognized the possibility that a functional claim could be inserted in the patent through inadvertence. In delivering the opinion of the court Mr. Chief Justice Taney observed: "Whoever discovers that a certain useful result will be produced in any art, machine, manufacture, or composition of matter, by the use of certain means, is entitled to a patent for it; provided he specifies the means he uses in a manner so full and exact that any one skilled in the science to which it appertains can, by using the means he specifies, without any addition to, or subtraction from them, produce precisely the result he describes. And if this cannot be done by the means he describes the patent is void. And if it can he done, then the patent confers on him the exclusive right to use the means he specifies to produce the result or effect he describes and nothing more. And it makes no difference, in this respect, whether the effect is produced by chemical agency or combination; or by the application of discoveries or principles in natural philosophy known or unknown before his invention; or by machinery acting altogether upon mechanical principles. In either case he must describe the manner and process as above mentioned, and the end it accomplishes. And any one may lawfully accomplish the same end without infringing the patent, if he uses means substantially different from those described."In sum, in O'Reilly v. Morse, Morse was allowed a patent for a process of using electromagnetism to produce distinguishable signs for telegraphy. (Id., at 111.) But the Court denied the eighth claim in which Morse claimed the use of "electro magnetism, however developed for marking or printing intelligible characters, signs, or letters, at any distances." Id., at 112. The Court in disallowing that claim said: "If this claim can be maintained, it matters not by what process or machinery the result is accomplished. For aught that we now know, some future inventor, in the onward march of science, may discover a mode of writing or printing at a distance by means of the electric or galvanic current, without using any part of the process or combination set forth in the plaintiff's specification. His invention may be less complicated - less liable to get out of order - less expensive in construction, and in its operation. But yet, if it is covered by this patent, the inventor could not use it, nor the public have the benefit of it, without the permission of this patentee." (Id., at 113.) In O'Reilly v. Morse, the Supreme Court of the United States was able to foresee the dangerous possibilities of extending the scope of a patent on telegraphic machinery to the transmission of words by electrical impulses, and to deny that extension on the Court's own knowledge. But today in the crowded field of chemical invention a court cannot even make a guess from its own experience as to the actual scope that a patent on a chemical formula may afford.